(a) Field of the Invention
The present invention relates to a key scaling apparatus for use in an electronic musical instrument to control such musical tone characteristics as tone volume, tone color and tone pitch for every note and for every note group constituted with the keys of the keyboard of the electronic musical instrument. More particularly, the present invention concerns an apparatus mentioned above for allowing the player of an electronic musical instrument equipped with this apparatus to realize an intended or desired key scaling to produce musical tones closely resembling the tones of a natural musical instrument.
(b) Description of the Prior Art
In the past, there has been known a key scaling apparatus for an electronic musical instrument, which is so designed that, from among preset limited fixed kinds of key scaling curves, an arbitrary one is selected by the player of the instrument to control the musical tones which are to be sounded out (for example, see Japanese Patent Preliminary Publication No. Sho 58-211786).
According to this known apparatus mentioned above, the player cannot but rely upon only several preset stereotyped key scaling curves (e.g. straightforward curves, exponential curves, etc.), so that they are not sufficient from the aspect of richness of expression of performance. More specifically, in the case of natural musical instruments such as guitar or piano for example, the produced tone quality differs with each string of the instrument. However, it has been practically impossible with the prior art key scaling apparatuses to adroitly express, by utilizing only those preset typical key scaling curves, subtle and delicate difference in the quality of respective musical tones which are sounded out. In order to solve this difficulty, key scaling curves for every kind of musical instrument may be provided. This, however, will lead to an enormous amount of tone control data which are to be stored in a memory, thus resulting in the inconvenience that a memory of a tremendously large capacity is required.